The University of Pennsylvania School of Medicine has begun a massive reinvestment in biomedical research and as part of that plan has allocated significant resources to the Department of Biochemistry and Biophysics in order to modernize its research space and capabilities and expand its faculty. Integral to this effort, the School of Medicine is establishing an advanced laboratory in structural biology which will initially encompass the technologies of NMR spectroscopy and X-ray crystallography. Space is being prepared to house three Xray diffractometers and six NMR spectrometers. This proposal seeks partial support for the NMR component of the laboratory. The University has an outstanding opportunity for the acquisition of state-of-the-art 750 MHz, 600 MHz and 500 MHz NMR spectrometers. These spectrometers will allow the optimal application of modern high resolution multinuclear and multidimensional NMR techniques to the structural, dynamic and energetic characterization of a wide array of proteins and their complexes with target ligands. The NMR-based studies include structural characterization of complexes between calmodulin - a central player in calcium mediated signal transduction - and calmodulin-binding domains of regulated proteins; discovery and demonstration of protein design principles using de novo designed alpha helical bundles of various topologies and construction of prosthetic group-binding bundles (maquettes); resolution of fundamental issues in protein folding mechanisms and principles; novel approaches to the design of membrane spanning synthetic proteins; investigation of electrostatic fields in proteins; comprehensive characterization of protein dynamics and energetics; and characterization of the structural and energetic foundation of the allosteric response in hemoglobin. The spectrometers will also provide support for two new research-track faculty to be hired in the very near future. In addition, the spectrometers will provide a core resource for the development of emerging techniques such as the use of high pressure NMR, NMR relaxation, and hydrogen exchange in a variety of contexts.